This question isn’t particularly about tools and machinery, but more of technique. When my wife and I were on honeymoon in Bali, we had made a traditional carving with the help of a local villager. At this point, the wood is quite dried out and is beginning to crack along the edges. I’d like to do a bit of work on it to square it up and maybe carve a design along the border. My questions are:

Do I need to “re-hydrate” the wood before I do any work on it and make any cuts using a table saw?

What is the best best product for re-hydrating, if that is indeed something I need to do first – linseed oil? Boiled linseed oil? something else?

Any particular type of finish I should use to keep the wood in good shape for the long term?